{
 "cells": [
  {
   "cell_type": "markdown",
   "id": "google",
   "metadata": {},
   "source": [
    "##### Copyright 2025 Google LLC."
   ]
  },
  {
   "cell_type": "markdown",
   "id": "apache",
   "metadata": {},
   "source": [
    "Licensed under the Apache License, Version 2.0 (the \"License\");\n",
    "you may not use this file except in compliance with the License.\n",
    "You may obtain a copy of the License at\n",
    "\n",
    "    http://www.apache.org/licenses/LICENSE-2.0\n",
    "\n",
    "Unless required by applicable law or agreed to in writing, software\n",
    "distributed under the License is distributed on an \"AS IS\" BASIS,\n",
    "WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n",
    "See the License for the specific language governing permissions and\n",
    "limitations under the License.\n"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "basename",
   "metadata": {},
   "source": [
    "# crossword2"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "link",
   "metadata": {},
   "source": [
    "<table align=\"left\">\n",
    "<td>\n",
    "<a href=\"https://colab.research.google.com/github/google/or-tools/blob/main/examples/notebook/contrib/crossword2.ipynb\"><img src=\"https://raw.githubusercontent.com/google/or-tools/main/tools/colab_32px.png\"/>Run in Google Colab</a>\n",
    "</td>\n",
    "<td>\n",
    "<a href=\"https://github.com/google/or-tools/blob/main/examples/contrib/crossword2.py\"><img src=\"https://raw.githubusercontent.com/google/or-tools/main/tools/github_32px.png\"/>View source on GitHub</a>\n",
    "</td>\n",
    "</table>"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "doc",
   "metadata": {},
   "source": [
    "First, you must install [ortools](https://pypi.org/project/ortools/) package in this colab."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "install",
   "metadata": {},
   "outputs": [],
   "source": [
    "%pip install ortools"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "description",
   "metadata": {},
   "source": [
    "\n",
    "\n",
    "  Crosswords in Google CP Solver.\n",
    "\n",
    "  This is a standard example for constraint logic programming. See e.g.\n",
    "\n",
    "  http://www.cis.temple.edu/~ingargio/cis587/readings/constraints.html\n",
    "  '''\n",
    "  We are to complete the puzzle\n",
    "\n",
    "     1   2   3   4   5\n",
    "   +---+---+---+---+---+       Given the list of words:\n",
    " 1 | 1 |   | 2 |   | 3 |             AFT     LASER\n",
    "   +---+---+---+---+---+             ALE     LEE\n",
    " 2 | # | # |   | # |   |             EEL     LINE\n",
    "   +---+---+---+---+---+             HEEL    SAILS\n",
    " 3 | # | 4 |   | 5 |   |             HIKE    SHEET\n",
    "   +---+---+---+---+---+             HOSES   STEER\n",
    " 4 | 6 | # | 7 |   |   |             KEEL    TIE\n",
    "   +---+---+---+---+---+             KNOT\n",
    " 5 | 8 |   |   |   |   |\n",
    "   +---+---+---+---+---+\n",
    " 6 |   | # | # |   | # |       The numbers 1,2,3,4,5,6,7,8 in the crossword\n",
    "   +---+---+---+---+---+       puzzle correspond to the words\n",
    "                               that will start at those locations.\n",
    "  '''\n",
    "\n",
    "  The model was inspired by Sebastian Brand's Array Constraint cross word\n",
    "  example\n",
    "  http://www.cs.mu.oz.au/~sbrand/project/ac/\n",
    "  http://www.cs.mu.oz.au/~sbrand/project/ac/examples.pl\n",
    "\n",
    "\n",
    "  Also, see the following models:\n",
    "  * MiniZinc: http://www.hakank.org/minizinc/crossword.mzn\n",
    "  * Comet: http://www.hakank.org/comet/crossword.co\n",
    "  * ECLiPSe: http://hakank.org/eclipse/crossword2.ecl\n",
    "  * Gecode: http://hakank.org/gecode/crossword2.cpp\n",
    "  * SICStus: http://hakank.org/sicstus/crossword2.pl\n",
    "  * Zinc: http://hakank.org/minizinc/crossword2.zinc\n",
    "\n",
    "  This model was created by Hakan Kjellerstrand (hakank@gmail.com)\n",
    "  Also see my other Google CP Solver models:\n",
    "  http://www.hakank.org/google_or_tools/\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "code",
   "metadata": {},
   "outputs": [],
   "source": [
    "from ortools.constraint_solver import pywrapcp\n",
    "\n",
    "\n",
    "def main():\n",
    "  # Create the solver.\n",
    "  solver = pywrapcp.Solver(\"Problem\")\n",
    "\n",
    "  #\n",
    "  # data\n",
    "  #\n",
    "  alpha = \"_abcdefghijklmnopqrstuvwxyz\"\n",
    "  a = 1\n",
    "  b = 2\n",
    "  c = 3\n",
    "  d = 4\n",
    "  e = 5\n",
    "  f = 6\n",
    "  g = 7\n",
    "  h = 8\n",
    "  i = 9\n",
    "  j = 10\n",
    "  k = 11\n",
    "  l = 12\n",
    "  m = 13\n",
    "  n = 14\n",
    "  o = 15\n",
    "  p = 16\n",
    "  q = 17\n",
    "  r = 18\n",
    "  s = 19\n",
    "  t = 20\n",
    "  u = 21\n",
    "  v = 22\n",
    "  w = 23\n",
    "  x = 24\n",
    "  y = 25\n",
    "  z = 26\n",
    "\n",
    "  num_words = 15\n",
    "  word_len = 5\n",
    "  AA = [\n",
    "      [h, o, s, e, s],  # HOSES\n",
    "      [l, a, s, e, r],  # LASER\n",
    "      [s, a, i, l, s],  # SAILS\n",
    "      [s, h, e, e, t],  # SHEET\n",
    "      [s, t, e, e, r],  # STEER\n",
    "      [h, e, e, l, 0],  # HEEL\n",
    "      [h, i, k, e, 0],  # HIKE\n",
    "      [k, e, e, l, 0],  # KEEL\n",
    "      [k, n, o, t, 0],  # KNOT\n",
    "      [l, i, n, e, 0],  # LINE\n",
    "      [a, f, t, 0, 0],  # AFT\n",
    "      [a, l, e, 0, 0],  # ALE\n",
    "      [e, e, l, 0, 0],  # EEL\n",
    "      [l, e, e, 0, 0],  # LEE\n",
    "      [t, i, e, 0, 0]  # TIE\n",
    "  ]\n",
    "\n",
    "  num_overlapping = 12\n",
    "  overlapping = [\n",
    "      [0, 2, 1, 0],  # s\n",
    "      [0, 4, 2, 0],  # s\n",
    "      [3, 1, 1, 2],  # i\n",
    "      [3, 2, 4, 0],  # k\n",
    "      [3, 3, 2, 2],  # e\n",
    "      [6, 0, 1, 3],  # l\n",
    "      [6, 1, 4, 1],  # e\n",
    "      [6, 2, 2, 3],  # e\n",
    "      [7, 0, 5, 1],  # l\n",
    "      [7, 2, 1, 4],  # s\n",
    "      [7, 3, 4, 2],  # e\n",
    "      [7, 4, 2, 4]  # r\n",
    "  ]\n",
    "\n",
    "  n = 8\n",
    "\n",
    "  # declare variables\n",
    "  A = {}\n",
    "  for I in range(num_words):\n",
    "    for J in range(word_len):\n",
    "      A[(I, J)] = solver.IntVar(0, 26, \"A(%i,%i)\" % (I, J))\n",
    "\n",
    "  A_flat = [A[(I, J)] for I in range(num_words) for J in range(word_len)]\n",
    "  E = [solver.IntVar(0, num_words, \"E%i\" % I) for I in range(n)]\n",
    "\n",
    "  #\n",
    "  # constraints\n",
    "  #\n",
    "  solver.Add(solver.AllDifferent(E))\n",
    "\n",
    "  for I in range(num_words):\n",
    "    for J in range(word_len):\n",
    "      solver.Add(A[(I, J)] == AA[I][J])\n",
    "\n",
    "  for I in range(num_overlapping):\n",
    "    # This is what I would do:\n",
    "    # solver.Add(A[(E[overlapping[I][0]], overlapping[I][1])] ==  A[(E[overlapping[I][2]], overlapping[I][3])])\n",
    "\n",
    "    # But we must use Element explicitly\n",
    "    solver.Add(\n",
    "        solver.Element(A_flat, E[overlapping[I][0]] * word_len +\n",
    "                       overlapping[I][1]) == solver\n",
    "        .Element(A_flat, E[overlapping[I][2]] * word_len + overlapping[I][3]))\n",
    "\n",
    "  #\n",
    "  # solution and search\n",
    "  #\n",
    "  solution = solver.Assignment()\n",
    "  solution.Add(E)\n",
    "\n",
    "  # db: DecisionBuilder\n",
    "  db = solver.Phase(E + A_flat, solver.INT_VAR_SIMPLE, solver.ASSIGN_MIN_VALUE)\n",
    "\n",
    "  solver.NewSearch(db)\n",
    "  num_solutions = 0\n",
    "  while solver.NextSolution():\n",
    "    print(E)\n",
    "    print_solution(A, E, alpha, n, word_len)\n",
    "    num_solutions += 1\n",
    "  solver.EndSearch()\n",
    "\n",
    "  print()\n",
    "  print(\"num_solutions:\", num_solutions)\n",
    "  print(\"failures:\", solver.Failures())\n",
    "  print(\"branches:\", solver.Branches())\n",
    "  print(\"WallTime:\", solver.WallTime())\n",
    "\n",
    "\n",
    "def print_solution(A, E, alpha, n, word_len):\n",
    "  for ee in range(n):\n",
    "    print(\"%i: (%2i)\" % (ee, E[ee].Value()), end=\" \")\n",
    "    print(\"\".join(\n",
    "        [\"%s\" % (alpha[A[ee, ii].Value()]) for ii in range(word_len)]))\n",
    "\n",
    "\n",
    "main()\n",
    "\n"
   ]
  }
 ],
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